No- I think there is a more sinister reason.
FEMA bigwigs and shrubs cronies don't want survivors winding up in a "liberal" city, where they would have very good access to tell thier story of abandonment and abuse by the feds. Hell, here in Portland someone might go rent a tripod and use em to make a documentary, which people might just see.
No, better to warehouse them in a huge concrete metropolis like Houston. The general population will likely ignore them. "Conservative" editors will get rid of any intelligent news from these folks and put together infomercials of army helicopters pulling white people off roofs for the 06 elections..
just my two cents